Thermal performance analysis of compact-type simulative battery module with paraffin as phase-change material and flat plate heat pipe

The thermal management of lithium-ion batteries is crucial for electric vehicles because of the optimum operating temperature and safety issues. Herein, we propose two types of compact battery thermal management systems (BTMS), which utilize a phase-change material (PCM), i.e., paraffin and flat plate heat pipes with liquid water cooling. The configurations are classified using the heat pipe installation method as the detached heat pipe (DHP) mode and attached heat pipe (AHP) mode. The thermal performance of the proposed BTMSs is characterized experimentally, and it is verified that the proposed AHP installation mode successfully managed the thermally stable operating conditions of the BTMSs. PCM melting is predicted using computational fluid dynamics and verified via experimental visualization. At a low heat generation rate of 2 W (544.39 W/m²), the PCM remained in the solid state. Melting occurred at higher heat generation rates of 4 and 6 W (1088.79 and 1633.18 W/m², respectively). At the coolant inlet temperature, the module's maximum temperature decreased significantly; however, the temperature difference within the module increased, which can cause thermal imbalance in the battery module.